html, body {
    min-width: 450px;
    min-height: 700px;
}
:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
    --background-color: #f8f9fa;
}

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    line-height: 1.6;
    padding: 1rem;
    background-color: var(--background-color);
    color: var(--primary-color);
    width: 100%;
    height: 100%;
    box-sizing: border-box;
}

h2 {
    color: var(--accent-color);
    border-bottom: 2px solid;
    padding-bottom: 0.5em;
}

textarea {
    width: 100%;
    height: 100px;
    margin: 1rem 0;
    padding: 0.8rem;
    border: 2px solid #ddd;
    border-radius: 6px;
    font-family: 'Consolas', monospace;
    transition: border-color 0.3s ease;
    resize: vertical;
}

textarea:focus {
    border-color: var(--accent-color);
    outline: none;
}

.button-group {
    margin: 1rem 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

button {
    padding: 0.8rem 1.5rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: opacity 0.3s ease;
}

button:hover {
    opacity: 0.9;
}

button:active {
    transform: scale(0.98);
}

nav {
    margin-bottom: 1.5rem;
}

nav button {
    background-color: #ddd;
    color: #333;
    margin-right: 0.3rem;
}

nav button.active {
    background-color: var(--accent-color);
    color: white;
}

section {
    display: none;
}

section.active {
    display: block;
}